Audible signaling device



March 29, 1949. MILLER 2,465,655

AUDIBLE S IGNALING DEVICE Filed Nov. 2, 1946 4 Sheets-Sheet l 9 7/ M INVENTOR CHR/S 7'/AN M/LLER L771 BY March 29, 1949. c. MILLER AUDIBLE SIGNALING DEVICE 4 Sheets-Sheet 2 Filed NOV. 2, 1946 2-6 INVENTOR CHRIS TIA/V MILLER Y 25 {hm Z6 2Z ATTORNEY ///%4% ZZAV E, 495720 March 29, 1949. c; MILLER AUDIBLE SIGNALING DEVI-CE 4 Sheets-Sheet 3 Filed Nov. 2, 1946 m\ R WY WM R mmw H March 29, 1949. c. MlLLER AUDIBLE SIGNALING DEVICE 4 Sheets-Sheet 4 Filed Nov. 2, 1946 lNVENTOR CfiR/sr/AA/ M/LLEF? ATTORNEY Patented Mar. 29, 1949 AUDIBLE SIGNALING DEVICE Christian Miller, Norwalk, Conn, assignor to Edwards & Company, Inc., Norwalk, Conn., a corporation of New York Application November 2, 1946, Serial No. 707,469

10 Claims.

This invention relates to audible signalling devices, more particularly to signalling devices to sound one or more musical notes.

One of the objects of this invention is to provide a practical signalling device of the abovementioned kind that will be of simple construction and action, capable of ready assembly in manufacture, and well adapted to meet varying requirements of practical use. Another object is to provide a signalling device of the just mentioned character so constructed that, with little change or rearrangement of parts, it will be capable of easy, inexpensive and quick adaptation for operation by various kinds of actuators according to the desired use to which the device is put, such as, for example, automatic actuation by the opening or closing of a door, manual actuation as at the front door of an apartment or dwelling, manual actuation as when used as a desk or table signal, and the like.

Another object is to provide an improved signalling mechanism in which the striker or strikers that coact with a sounding element or elements are controlled and actuated in an improved way and by simpler and more reliable mechanism. Another object is to provide a mechanism of the last mentioned kind that will be of improved construction and action, simple to fabricate and assemble, and more dependably achieve the desired striking action, including, where employed, improved successive striking of more than one sound element. Another object is to provide a mechanism of the last mentioned character that will facilitate adaptation of the signalling device to various modes or control of operation. Other objects will be in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts as will be exemplified in the structure to be hereinafter described and the scope of the application of which will be indicated in the following claims.

In the accompanying drawing in which are shown illustratively several of the various possible embodiments of this invention,

Figure 1 is a fragmentary small-scale elevation showing the signalling device mounted for actuation by the movement of a door;

Figure 2 is a fragmentary small-scale plan viewshowing the device arranged as a table or desk signal;

Figure 3 is an end elevation as seen along line 33 of Figure 1;

Figure 4 is an end elevation as seen along the line 44 of Figure 2;

Figure 5 is a perspective view of an internal supporting element of which a number are employed;

Figure 6 is a plan view or elevation, certain the parts being shown in section or broken away, of the device arranged to be actuated by a door;

Figure '7 is a vertical sectional view as seen along the line 1-'l of Figure 6;

Figure 8 is a transverse sectional View as seen along the line 88 of Figure 6;

Figure 9 is a perspective view of a combined mounting and bearing element employed in the construction;

Figure 10 is a plan view, certain parts being broken away and shown in section, of the signalling device arranged as a table or desk signal;

Figure 11 is an elevation, as seen from the inside of a door panel, wall, or the like, of the signalling device arranged for actuation from the other side of the Wall or panel;

Figure 12 is a plan view on a larger scale of an operating hub member employed in the construction of Figure 11;

Figure 13 is a center vertical sectional view thereof as seen along the line l3l3 of Figure 12;

Figure 14 is a vertical sectional view as seen along the line l4l4 of Figure 11, certain parts being shown in elevation;

Figure 15 is an elevation as seen from the left in Figure 14 showing the actuating mechanism on the other side of the wall or door panel.

Similar reference characters refer to similar parts throughout the several views of the drawings.

Referring first to Figures 6, '7 and 8, the signalling unit comprises a base 20 preferably of sheet metal and peripherally flanged, to rest against the desired supporting surface, the base having suitable holes 2! by which it may be secured to the supporting wall, door panel or the like, when desired, as by screws 22. Adjacent the longitudinal side edges of the base 20 are mounted two sounding elements 23 and 24, illustratively in the form of rectangular metal plates, sometimes called chime plates or chime bars, and where they are to emit difierent notes they are correspondingly differently dimensioned as indicated or suggested in the drawings. They are suitably supported, each preferably at two spaced points which preferably coincide with internodes, and the two supports for each bar preferably include a suitable yieldable material such as soft rubber, felt or the like, to minimize interference With sound-emitting vibration. Each mounting therefore preferably comprises a support and bushing of such yieldable material and all of the mount ings are preferably identical in construction, and hence it will suflice to describe only one of them in detail.

In Figure 5 such a mounting is shown in perspective. It comprises an L-shaped sheet metal stamping generally indicated by the reference character 25, having a fiat base 21 to rest against the sheet metal base 20 that is provided with suitable holes through which are passed the spaced ears 28 (Figure 5) which are then bent over on the under-side to secure the mounting in place. Upstanding from the base 21 is a vertical leg 29 which has cut and bent out of its plane a long arm or leg 33 that extends at right angles to the part 29 to receive a rubber or felt bushing 3|, which is held assembled thereto by the bent-over outer end of the arm 30.-

In Figure 6 four such mountings 26 are shown secured to the base 2.8 in appropriately spaced relation to support the chime bars 23 and 24 in substantial parallelism and in spaced relation, the yielding bushings 3| of the mountings passing through holes in the chime bars that are located at the internodes and the bushings M being preferably peripherally grooved as shown in Figure 5 to a diameter commensurate with the diameter of the holes in the chime bars into which the bushings are strained.

Preferably I provide for the successive striking of the two sounding elements 23 and 2t and in that case a single cycle of operations may comprise the striking first of one and then of the other. Intermediate of the chime bars 23 and 24 I provide a striker 32 (Figure 6) having opposed striking elements 33 and 33 which are preferably made of a suitable wood or plastic material. The striker 32 is mounted substantially at the midpoint of a flat or leaf spring 35 made of any suitable fiat spring material such as spring steel and shaped to provide end tongues 35 and 31 (see Figure 7) to facilitate supporting the spring at its two ends. The striker 32 preferably is given some weight or mass according to the inertia which it is desired that it have when set into motion, and conveniently can be made of metal, comprising two cylindrical parts 32 and 32 which are internally threaded and are mounted on either side of the spring 35 by a threaded headless stud 32 which passes through a suitable hole in the spring 35, the two parts 32 32 serving as nuts to clamp the spring 35 therebetween. The striker elements 33, 34 are conveniently threaded into the outer ends of the parts 32 32 respectively.

I have found numerous advantages if the spring 35 is supported .at each of its ends in a resilient and yieldable mounting, and then provide means that operate upon the spring intermediate of its ends for effecting changes in the direction in which the spring is to be bowed for effecting striking of a sounding element. Considering first the resilient mountings for the two ends of the springs, they preferably comprise springs which conveniently and preferably take the form of flat or leaf springs 38 and 39 that extend transversely of the general direction of the flat spring 35, they conveniently comprise any suitable fiat spring stock such as spring steel, and are provided at their respective ends with holes to receive yieldable bushings 3| of mountings 26, identical to those mountings above described for supporting the chime bars and hence being located and secured in position by corresponding holes in the base 23 through which the ears 28 (Figure 5) extend to be bent over underneath the base 23. With this arrangement many advantages are achieved in utilizing the needed number of identical parts such as the mountings 26 of Figure 5.

The mounting cross-springs 38, 39 are also preferably identical and are d mensioned or constructed to have the desired degree of resiliency or yield under the forces imposed thereon by the action of the flat bowed spring 35, forces which are applied at substantially the midpoints of the mounting'springs 38, 39 wherethe latter are given supports at both ends. 1

Each supporting spring 38, 39 has a central rectangular hole as indicated at 38 and 38 in Figures 6 and '7 to receive the tongue ends 36 and 31 respectively of the spring 35 which is thereby held againstv turning out of a plane that is at right angles to the base 20. To lessen the effacts of metal-to-metal contact, I interpose washers 42. and 43 between the ends of the spring 35 and the supporting springs 38 and 35 respectively, the washers being made of any suitable cushioning material such as felt, relatively soft rubber or the like, and they may thus also take part in the resilient action at the supported ends of the spring 35. The tongue ends 36, 3! pass through the washers and thus the latter are held against displacement.

The several parts thus far described are so dimensioned and interrelated, as indicated in Figure 6 and as described above, that the fiat spring 35, in its at-rest position to one side or the other of the Vertical axis in Figure 6 where it is shown to the right of that vertical axis, is bowed, and preferably to an extent that there exists a spacing between the striker element (either element 33 or 34) and the adjacent chime or sounding element (either 23 or 24) so that the striker element is normally held out of engagement' with the sounding element. Spring 35 is bowed, and under its tendency to straighten out, its ends exert forces upon the supporting crosssprings 38 and 39 and thus flex or how them in directions away from each other, somewhat as shown in Figure 6. The resiliency or yieldability of the bushings 3| that extend through the crosssprings 38 and 39 give the supports at the ends of the springs substantial flexibility and range of relative movement to provide virtually universal supports, being self-adjusting to the changing conditions that accompany changes in flexing of the cross-springs 3B and 39 themselves.

Spaced substantially from an end of the bowed striker actuating spring 35 I provide means. to apply force to the bowed spring 35 in a direction to effect reversal of the bowed condition of the spring and this means preferably comprises two lever arms 45 and 43 (Figures 6, 7 and 8), one to each side of the spring so that either may apply the force according to the direction in which the spring is to be bowed. Preferably the lever arms are provided with suitable cushioning means such as knobs or bush ngs 4'! and 48 of rubber to avoid metal-to-metal contact thereof with the spring 35 and preferably there is a substantial spacing between these spring engaging parts of the two lever arms.

The latter are preferably carried by a shaft 49 to which the lever arms are secured in any suitable manner or they may be integrally formed therewith, and to achieve the above-mentioned spacing the arms may be divergent as shown in Figure 8. 7

Suitable means are provided for rotatably supporting the shaft 49 so that it may be oscillated to actuate the spaced lever arms 45-4 5 and such means may comprise a combined bearing and mounting member generally indicated by the reference character 50 and shown also in Figure 9 in detached perspective. It may comprise a relatively heavy sheet-metal stamping having a flat securing portion 5| to rest against a the base 20 against which also the, shaft 49 rests (see Figure 8), and having one or more, illustratively two, bearing portions 52 and 53 which are substantially U-shaped in cross-section to overlie the shaft 49 and with the base plate closing off the U-shaped bearing portions the shaft 49 is thus supported for oscillating or rocking rotary movement. The member 50 may be secured to the base plate 20 as by screws 54 (Figure 6) threaded into the base plate 28, the securing portion 5| having suitable holes as shown in Figure 9.

One of the U-shaped bearing members, preferably the member 53, is cut away to provide a slot 56 to accommodate a pin 57 (Figures 6 and 8) force-fitted into a suitable radially extending hole in the shaft 49, the end walls of the slot 56 coacting with the pin 51 to limit the are or range of rocking movement of the shaft and of the lever arms 45 and 46 to the desired extent.

As shown in Figure 6, shaft 49 is provided with another pin 58 force-fitted into a radially extending hole and positioned at the other end of the bearing member 53 so that, in coaction with the pin 51, axial movement of the shaft 49 relative to its bearings is precluded and the spaced lever arms 45, 46 are held for force-applying movement to the bowed spring at the desired point along the length of the spring 35.

Extending about the shaft 49 is a coiled spring 60, one end of which is shaped into a hook or :1

loop 6| which engages over the pin 58 and the other end 62 engages with a fixed part, conveniently the part 5| of the bearing member 50. Spring 60 is tensioned to bias the shaft 49 in clockwise direction as viewed in Figure 8 and With the shaft 49 in its biased position as just described, lever arm 46, which is preferably bendable for adjustment purposes, occupies a position to the right of the spring 35 (bowed toward the right as in Figure 6) so that its springengaging part. namely bushing 48, is spaced materially from the spring 35. When the spring 35 is bowed to the left from the position shown in Figure 6 and the shaft 49 rocked counter-clockwise from the position shown in Figure 8 to the extent permitted bv the left-hand end wall of slot 55, a similar relationship will exist between the bowed spring 35 and the lever arm with its rubber bushi g 41. Lever arm 45 is also preferably bendable for adjustment purposes. With this relationship of the parts. the spacing between the sprin -engaging portions of the levers 45 and 46. that is, the spacing between the bushings 41 and 48, is less than the range of transverse movement of that portion of the spring 35 that extends between them as the spring undergoes change or reversal from one bowed position to the other.

If the shaft 49 is rocked in counterclockwise direction in Figure 8, against the bias of spring 60, part 48 moves transversely into engagement with the bowed spring 35, and applies a transverse (to the left) force to the spring at a point substantially spaced from either of its ends. thus gaining a substantial mechanical advantage and requiring less force than if the spring-distorting force were applied at or closely adjacent to an end of spring 35. As the force application continues spring 35 is distorted, passing from the single curvature or bowing as shown in Figure 6 through a double curvature somewhat like an ogee curve, its lower half being convex toward the left and its upper half being convex toward the right, whence it somewhat suddenly snaps over into a single curvature that is the reverse of that shown in full lines in Figure 6, thus reversing its bowed condition. In undergoing this transition the two end cross-springs 38 and 39 become more tensioned or more bowed, thus lengthening somewhat the spacing of the effective supports at the ends of the spring 35 and washers 42 and 43 become more compressed. As the spring snaps over into reverse bowed condition, the energy stored in these tensioned and compressed parts is released, acting upwardly at the lower end of the spring 35 and downwardly at the upper end and thus giving greater impetus to the snap action with which the spring reverses its bowed condition.

By the time that the spring 35 commences snapping into reverse bowed shape, the counterclockwise swing of shaft 49 has just about reached its limit and pin 51 is about to engage the left-hand end wall of stop slot 56, and that position of the shaft brings the other lever arm 45 and the bushing 41 to such a position to the left of that shown in full lines in Figure 6 that it is not in the path of continued bowing movement of the spring 35 to the left.

The snap action of the spring 35 in reversing its bowed condition gives the striker structure 32 a relatively high veloc ty of movement to the left and the energy thereby stored in the striker, or its inertia, carries it to the left beyond what would be the normal at-rest position of the parts, causing the striker element 33 to give the chimebar 23 an energetic blow and setting it into vibration. This action can be aided by the above described forces resulting from the energy stored in the resilient and yielding supports at the two ends of the spring.

Having struck the chime bar 23, the striker structure rebounds and assumes a position in which the striker element 33 is spaced from the chime bar 23 by about the same distance that the striker element 34 is indicated in Figure 6 as being spaced from the chime bar 24. Spring 35, in assuming the reversibly bowed condition, that is to the left, rema ns spaced from the lever arm 45 and rubber bushing 41, and if shaft 41 is now swung in counterclockwise position (Figure 8), lever part 41 moves to the right and into engagement with the spring 35 to distort the spring and cause it to reverse its bowed condition, again with a snap action, to impact the striker element 34 against the other chime bar 24, lever arm 46 and rubber bushing 48 moving out of the path of rightward movement of the spring 35, the parts coming to rest, upon rebound of the striker structure, in position substantially as shown in Figure 6. The reverse rocking stroke of the shaft 49 can be effected by the release of the energy stored in the spring 66 during the initial stroke.

Fitted over the entire assembly and secured in any suitable way (not shown) tothe base 29* is a box-like cover which can be in the form of a sheet metal stamping and telescopically fitted over the flanges of the base 20 as shown in Figures 7 and 8. Suitablewalls of the cover 65, preferably the side walls 66 and 61, that are respectively adjacent the sounding elements 23 and 24 are provided with suitable holes or apertures 68 for better sound emission, the entire closure functioning as a resonator to improve the anew 7 quality of sound emitted: by the vibratable chime bars,

The lower: end walli 1c as seen in: Figures fi and 7 of the cover 65' is provided with a slot N that is in line with the shaft 49; When it is desired to install the device and actuate it as a signal to indicate the opening of a door, shaft 49' is given a length such that it extends through the slot H and beyond the lower end wall of the cover. In such case the device is mounted, as by securing the base with the aid of screws 22 (Figure 7) to the upper part of a door-frame 13 as shown in Figure 1, with the projecting portion of shaft 49 extending horizontally. To the shaft 49- is secured an actuating device generally indicated by the reference character 14 and better shown in Figures 3 and 6; and constructed preferably to respond to door-opening movement but not to door-closing movement. The device 14 is preferably adjustable and-preferably comprises a heavy strap metal part 15 bent to form a loop l6 to receive the projecting end of shaft 421 and provided with a screw 11 for clamping theloop securely to the shaft 49-. With this arrangement the angularity, illustratively that shown in Figure 3, of the actuating lever part 15 may be adjusted or set during installation of the signalling device. Part 15' isprovided with a lot 18 (Figure 6) and underlying it is aheavy sheet metal lever part 8!! that has two spaced screws 8 I- threaded into it and passing through the slot 78, whereby the effective lever arm or length of the device 14 as a whole may be adjusted during the installation.

The lower end of lever part 80 is provided'wi-th spaced upstanding ears 84 which are apertured to receive the trunnions 82 of a door-engaging part 53 which is in the-form of a lever of the first-class having a part 83 that can engage the lever part 89 and having a portion 83 preferably formed into a rounded-over loop (see Figure'3), for coaction with the door 85 (Figures 1 and 3) as the latter moves inopening; direction, a direction to the right in Figure 3. Where the door is hinged at the right as shown in Figure 1, the signallingv device is preferably mounted so that the pivoted lever 83 hangs down in the path of the door near its left-hand upper edge and were the door to be hinged at its left the signalling device is simply mounted more to the right on the door frame 13 and also to position the pendant lever 83 in the path of opening movement of that portion of the door remote from the hinge.

Accordingly as the door 85 opens or moves to the right in Figure 3, the rounded-over part 83 is engaged by the door and the door swings the pendant lever 83 in counterclockwise direction until the part 83*- engages the part 80 whereupon the continued opening movement of the door causes the adjustable lever 15-80 to be swung in counterclockwise direction throughout such an are as corresponds to the raising of the device 74 necessary for the door 85 to by-pass it. By the above described adjustments of the parts relative to each other and to the door 85, that are of swing, communicated to the shaft 49, corresponds substantially to the initial counterclockwise rocking stroke of shaft 49 as described in connection with Figures 6, '7 and 8, being effective to reverse the bowing of springs and cause the chime bar 23 to be struck, and energy stored in the spring 60 Once the door has passed out of engagement with thepart 83 the energy stored in spring 60 is freed to give the shaft its 7 reverse stroke ofvrotary movement andv toreverse the: bowing oiflat. spring 3'5? to cause: the striking of the chime bar Eli, and; at the same time to restore the: door actuator structure '14 Figures 2' and 4, it simply rests on the table or desk. by way of the interengaged flanges of the base 29 and walls of the cover 65 and the projecting end of shaft 59 has secured to it a lever 88 at the free end of which it carries a fingerpiece 81 (Figures 2', 4 and 10). The lever 86 is preferably adjustably secured to the projecting shaft portion as by forming the lever 86 out of suitably heavy strap metal, and shaping it into a clamping loop 86 (Figure l) to clamp the shaft d9; under the clamping pressure applied by a clamping screw 88. Where the initial rocking stroke of the shaft 4-9 is in counterclockwise direction" as seen in Figure 8 and also in Figure 41, the finger lever 88 is so mounted tothe shaft &9, as shown in Figure 4, that a depressing movement of-the lever effects the first rotary stroke of the shaft 49 to cause one sounding. element to be struck, the spring 613 giving the shaft 49 its second and reverse stroke, thus to cause the other chi-mebar to be struck and to restore the finger lever 86 to upward position for subsequent manual actuation.

Where it is desired to' install the signallingv device for actuation bya caller at the door of an apartment, dwelling or the like it is secured in position, as shown in Figure 14, on one side of the wall or door panel, indicated at 90, and an actuating mechanism generally indicated at- 9| is mounted on the other side. For such an installation the shaft 49" of Figures 6 and 7' is replaced by a shortershaft 49 -as shown in Figures 11 and 14, shaft 49* being exactly like shaft 49 excepting that it terminates just beyond the inner end '53 of the mounting and bearing part 50 of Figure 9 to a sufficient extent to carry the above described pin 58 (see Figure 11). It also has the pin 51 coacting' with the stop slot 56 and a coiled spring 60 is also provided but oneend of it is looped as at 6i onto the pin 5"! and the other end 82 rests against a fixed part such as the base 20, in order thus to bias the shaft w just as the shaft 49 of Figures 6, 7 and 8' is biased. In the latter figures, in order to accommodate the spring 60, the underlying portion of the base 28 is drawn and flanged or depressed (to the r'ght in Figure 7) as indicated at 20?, having around hole 92 in the depressed portion which thusprovides an annular hearing or ledge. In Figures 11' and 14, with the spring (ill about the upper end of the shaft, the base 20 is simply provided with a large hole 93 into which the turns of the spring can project.

The annular ledge 26 and the walls of, the hole 92 form stepped bearing surfaces for a rotary member generally indicated by the reference character 95- and better shown in Figures 12 and 13. Member 95 comprises a cylindrical hub 98 having a square hole 99 extending coaxially therethrough; its lower end is of a diameter to neatly fit into the hole 92 (Figure 14) and it has a peripheral. flange Hill which is just accommodated in the annular bearing seat formed by the. annul'ar drawn and flanged part 2t! so that the lefthand face of the part I falls in the same plane with the left-hand face of the base 20.

The spacing between the bearing parts 52 and 53 of the device 50 (Figures 9 and 11) is such that when the part 50 is put in position and secured to the base 20, the flange part I00, flush with the face of base 20, is prevented from moving out of the annular bearing seat formed for it by the draw or flange 20*, because, as shown in Figure 11, at least four substantially uniformly spaced parts of the device 50 overlie the flange I00, and thus the part 95 is dependably mounted for rotary movement about an axis at right angles to the axis of shaft 49* which terminates closely adjacent to the hub part 98 (Figures 11 and 14). The hub part 98 projects beyond the plane of the uppermost portions of the bearing parts 52 and 53 and has secured to it a disc IGI (Figures 11-14) which is provided with suitable extensions, like teeth, to provide a radially extending slot I02 of substantial length and in which is received the pin 58 (see Figure 11) carried by the shaft 49 In the wall or door panel 90 is a hole I03 (Figure 14) through which extends a square shaft I04 that passes into or through the square hole 99 in the hub 98 of the signalling device, its righthand end as seen in Figure 14 being turned down as at a e to provide a trunnion which is rotatably supported in a hole IIJ5 of a base plate I05 that forms part of the actuator structure 9|, which in turn is provided with any suitable manually operable means, preferably in the form of a lever I06 (see also Figure that simulates a door knocker in appearance, having a handgrip I055 at its lower end so that the arm I06 may be swung toward or away from the base or escutcheon plate I05 which is secured to the part 90 as by screws I01.

Projecting from the plate I05 are spaced ears or lugs I08 and I09 provided with holes to take a pivot pin or screw I I0 and the under side of the upper end of the arm I06 is shaped, as by casting, stamping, molding or the like, to provide two spaced ears I08 and I06 between which are received the ears I09 and I08 of the base plate I05 and also having holes therein for the pivot pin I II).

On the inside face of arm I06 is an ear I06 on which is secured or formed a curved rack or gear segment III, coaxially with the axis of pivoting which axis preferably intersects the axis of the square shaft I04. A gear segment I II meshes with a tooth or gear member I I2 which is secured to the rounded portion I04 of the shaft I04. Ear I06 has a hole in it for the passage therethrough of the pivot pins I I0.

The unit 9I thus mounted on the other side of the panel or wall 90, has its shaft extending through the hole I03 in the wall 90 and into the square hole 99 of the driving hub 98 and, depending upon the thickness of the wall or panel 90, the square shaft I04 can project (to the left in Figure 14) beyond the hub 98 to a substantial extent up to the front wall of the cover 65, and thus the signalling unit on the one side and the actuating unit on the other side can be accommodated to a wide range of thicknesses of wall or doors without having to change the length of the square shaft I04.

Upon swinging the manual lever or arm I06 counterclockwise in Figure 14, the square shaft is given a rotary stroke of movement which is communicated to the driving hub 98 which, through the pin and slot connections 58 and I02 (Figure 11) gives the shaft 49 and the lever arms 45 and 46 a stroke of rotary movement against the tension of the spring 60 to effect reversal of the bowing of the spring 35 and striking of one of the chime bars (chime 23), the movement of all of the driving mechanism, including the swing of the external actuator arm 1% of the unit 51 being limited by the coaction of the pin 5? with the slot 56. Upon release of the manual actuator I05, the energy stored in the spring 5% (Figures 11 and 14) effects a reverse actuation ancl drive of the parts, causing the other chime bar 24 to be struck and the driving mechanism and manual actuator I06 restored to normal position.

I claim:

1. An audible signalling apparatus comprising a resonator casing having therein two spaced sounding elements, a spring having striker means and extending in the space therebetween, said casing having means therein for supporting said spring at its ends, the distance between the supporting means being less than the length of the spring whereby the latter is supported in bowed condition toward or away from one of said sounding elements according as said spring is first strained and then snaps out of one bowed condition to reverse bowed condition, a springopposed rock shaft having bearing means in said casing for supporting it with its axis generally parallel to the line joining the ends of said spring, said shaft having two spaced arms for engaging one side or the other of said spring intermediate its ends according to the direction of swing of said shaft, operating means external to said casing and having connection with said shaft, and means limiting the arc of rocking of said shaft so that either arm may strain the spring to snapping position, the spacing between said two arms being greater than the length of the are through which that part of the spring that is engaged by an arm travels during that portion of the reversal of its bowing that corresponds substantially to its snapping movement that follows completion of straining movement by the arm, whereby on each stroke of the limited arc of swing the leading arm is out of the path of snap movement of the spring and is free from impeding the snap of the spring to strike a sounding element.

2. A signalling apparatus comprising a sounding element, a flat spring, a striker carried thereby, a pair of supports holding the ends of said flat spring, said supports being spaced apart by a distance less than the length of the spring whereby the latter is bowed toward or away from the sounding element, a rock shaft extending alongside an edge of said fiat spring substantially parallel to the line joining the ends of the spring, a pair of arms carried by said shaft extending to points on opposite sides of said spring and spaced apart by a distance sufficient to permit the leading one of said arms to be clear of said spring during rocking motion of said shaft in a direction to bring the other of said arms into engagement with a face of said spring to move the spring through a dead-center position to permit said spring to snap to its oppositely-bowed position, an actuating lever extending substantially radially from said shaft and an extension of said lever hinged to the end of said actuating lever, said lever and extension having ccacting abutments to stop the swing of said extension beyond a position of substantial parallelism with said lever in one direction, whereby said extension and lever act as a single lever to rotate said shaft in one direction to actuate said spring responsive to engagement of the end of said extension by a moving object, and said extension can swing independently in the opposite direction without rotating said lever and shaft.

3. A signalling apparatus as claimed in claim 1 in which said shaft extends through awall of said casing and said operatin means comprises a lever on the external portion of said shaft for rocking actuation of said shaft in opposition to its Spring, said lever having a finger piece whereby, when said casing rests on a horizontal surface, said finger piece may be depressed to effect sounding of said elements, said limiting means operating to limit the range of depressing movement of said finger piece,

4. A signalling apparatus as claimed in claim 1 in which said shaft extends through a wall of said casing and said operating means comprises a lever having two hingedly connected parts, one part being connected to said shaft externally of the casing and the other being enga-geable by a door or the like, the hinged connection between the two lever parts having coacting stop means to limit hinging action on only one direction of movement of the door and thereby eifect actuation of the rock shaft against the opposition of its spring, whereby in reverse direction of movement of the door the latter simply swings one lever part relative to the other without actuation of the rock shaft.

5. An audible signalling apparatus comprising a resonator casing having therein two spaced sounding elements, a spring having striker means positioned in the space between said sounding elements, two spaced supports for the ends of said spring, said supports being non-rotatable and extending substantially at right angles to said sounding elements, but being resilient in a direction substantially parallel with said sounding elements, the distance between said supports being less than the length of the spring whereby the latter is supported in bowed condition toward or away from one of said sounding elements according as said spring is first strained and then snaps out of one bowed condition to reverse bowed condition, a rock shaft extending parallel to the line joining the ends of said spring and having two spaced arms extending substantially at right angles to said rock shaft for engaging one side or the other of said spring intermediate its ends according to the direction of rotation of said shaft, and means for actuating said shaft.

6. An audible signalling apparatus comprising a resonator. casing having therein two spaced sounding elements, a spring having striker means and extending in the space therebetween, said casing having means therein for supporting said spring at its ends, the distance between the supporting means being less than the length of the spring whereby the latter is supported in bowed condition toward or away from one of said sounding elements according as said spring is first strained and then snaps out of one bowed condition to reverse bowed condition, a fork having its two spaced arms extending one to either side of said spring intermediate its ends and means mounting said fork for reversible movement transversely of a line joining the ends of said spring, the spacing between said arms being such that on each stroke of movement of the fork the leading arm is out of range of the snapping movement of the spring that takes place upon completion of spring-straining action by the trailing arm.

7. An audible signalling apparatus comprising two spaced sounding elements, a spring -extending in the space therebetween and having supporting means at its two ends spaced to support it in bowed condition, said spring carrying striker means intermediate its ends to impact said sounding elements according as said spring is strained and snaps out of one bowed condition to reverse bowed condition, a member at one side of said spring for applying force to the spring intermediate its ends to strain it out of one bowed condition, a member at the other side of said spring for applying force to the spring :intermediate its ends to strain it out of its other bowed condition, and means for actuating said twomembers, said actuatin means comprising means 'movably mounting said two members for reversible movement in directions generally transverse to the line joining the two ends of said springto effect force-application to the spring by one member and movement of the other member out of the path of snap-movement of the spring as the latter effects reversal of its bowed condition.

8. A signalling apparatus comprising a sounding element, aflat spring having striker means and having means supporting it at its ends, said supporting means being spaced apart by a distance less than the length of the spring whereby the latter is bowed toward or away from the sounding element, .said supporting means each comp-rising spring means biasing the IsuPDOlting means toward each other and tending to lessen said distance, and means for straining said spring and said spring means to efiect snap-over action of the flat spring to strike said sounding element.

9. A signalling apparatus as claimed in claim .8 in which said straining means comprises a fork having two spaced arms one in each side of said fiat spring.

10. A signalling apparatus as claimed in claim 8 in which said straining means comprises a fork having two spaced arms one in each side of said fiat spring, and resilient sound-damping means interposed between said ,flat spring and said two arms.

CHRISTIAN REFERENCES CITED The following references are .of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 150,388 Barton May 5.31.874 277,741 Jones May 15, 1883 770,437 Mayland Sept. 20, 1904 1,859,345 Schantz May 24, 1932 2,412,978 Fish Dec. 24, 1-946 

